Possible hydraulic leak on surface grinder

Hi,

I noticed what I think is a hydraulic fluid leak on a Boyar Schultz surface grinder. I believe this is probably an 80's era Challenger grinder. The hydraulics themselves work fine, but the leak is large enough that I think it needs to be addressed before I use the hydraulic system.

This is the area where I see fluid pooling up. I don't see an obvious source, but I suspect it's coming from behind or below the control box. As a point of reference, the knurled knob is the table travel speed adjustment.



Is this something that can be reasonably repaired? I'm guessing maybe the black sealing material between the plates is the leak. On a related not, while attempting to adjust the cushion settings, I stripped one of the silver screws (also in this photo). The thread is 10x32 so pretty fine thread. That's kind of a secondary problem right now and I think if I could just get that screw to seal, I could live with it.

If it's not repairable, is there any harm in continuing to use it and just keep the reservoir topped up?

Thanks,
Rob

Rob, I don't know your grinder, but just have a general comment. My two hydraulic grinders both leak oil in several places. BUT this leaking oil then drops onto sheet metal parts that guide it back into the sump. So the leaks are no problem.

Will the oil from your leak find its way back to the oil sump? If so, IMO just leave it as is, not worth fixing.

It would be better to post a photo of the fluid leaking out near the beginning of the leakage so we can actually get a better idea of where it might be coming from. That picture really doesn't convey much information in that respect. That's probably why you're not getting much in the way of answers. We can't see where the leak may be coming from, nor how bad it is.

Thanks guys,

Didn't think about the fact that it might actually be ok and I will post a photo with the leak. Should have done that originally.

On my KO Lee I traced the leak to a loose hose. Tightened the clamp all OK. The hardest part is seeing up in there.

metalmagpie said:

On my KO Lee I traced the leak to a loose hose. Tightened the clamp all OK. The hardest part is seeing up in there.

Click to expand...

You got that right :-). I'm hoping it's something similar. I'll try to get a shot underneath as well later today.

One of the DoAll grinders I used had a hydraulic system for operation, and the same oil system metered oil on the ways, but not recovered but drained into a pan.

Dave

I tried to reproduce the leak tonight and noticed a couple things. If I let the table just run back and forth without the cross feed activated, there wasn't a leak. But, if I activated the cross feed, I noticed a very small amount of leaking behind the control box. This is a photo showing the glimmer or a small leak behind the control mechanism.



Kind of tricky to get a shot, but you can probably see the glimmer of oil. However, after running for a few minutes there wasn't a noticeable leak (from the front of the machine). But, after shutting everything off and leaving the machine for a while (maybe 30 minutes), I see a pool of fluid visible beside the control box. It runs down the front of the machine and drips on the floor (No recovery).



It's hard to see in this photo, but there's a film of oil over this entire surface.

I also noticed a squishy sound when actuating the cross feed control lever which makes me think it's a leak in that valve or whatever the internal mechanism is that controls the cross feed. Not sure if that sound if normal, but seems like I'm hearing oil squishing whenever I move the cross feed level so maybe that's the actual underlying issue.

Thanks Dave,

As far as I can tell, mine works the same way. If I look under the machine (between the main grinder and the stand), I don't see a way to recover any fluids. When I first got the grinder, I literally scraped tons of grinder sludge out.

Tonight I tried to reproduce the leak and I think it might be related to the cross feed function. After running the table back and forth for minutes, I noticed no leak. But, when I moved the cross feed lever, I noticed a squishy sound as I moved the lever up and down and after waiting for a minute or two, I saw a slight amount of oil behind the control box.



A little hard to get a good shot behind the control box, but you can see a slight glimmer of oil. I then shut down the machine and after 10 minutes or so, I see a noticeable amount of oil on the front of the machine.



This looks similar to my earlier photo, but it's actually covered in a thin layer of oil that overflows and runs off the front of the machine to the floor so no recovery in this case.

The squishy sound on the lever is suspicious though and I suspect it's the culprit so maybe I'll need to break down the grinder so I can get good access to the control box or live with the leak for now.

The squishy sound may be caused by air getting into the system. Won't have any thing to do with the leak.

Check the oil level, a loose pick up tube (if the system uses one)a return line above the oil level or a worn pump shaft seal ( if it is an external mount pump).

If air is getting in the system the oil will look milkey or cloudy after it has run awhile. If so then take a sample and let it sit,if it clears up after a while then it is a sign of air entrainment.

Thanks! The oil I've seen looks clear, but that's good to know. I did finally download a pdf of the original manual and was able to replace the o-rings below the valve block. I think that might have helped with the leak and at least I was able to see that oil was leaking from the valve block and not somewhere else. So ultimately I might need to replace the gaskets that make up the valve block to eliminate the rest of the leak.